A wireless communication system for, for example, mobile telephones has proposed a Self Organization Network (SON) in order to automatically manage the configuration of the wireless communication system, optimize the performance of the system, and deal with problems. One of the proposed examples of SON uniformalizes traffic through the adjustment of transmission power of a wireless base station in which traffic is being concentrated and the peripheral base stations thereof. Specifically, the traffic load on each wireless base station is monitored and transmission powers at base stations are adjusted such that some of the mobile terminals accommodated by a concentrated base station in which traffic is concentrated, are newly accommodated by a peripheral base station under the control of a managing station such as an MME. Namely, transmission powers of the respective base stations are adjusted such that some of the mobile stations accommodated by the concentrated base station are accommodated by the peripheral base station (that is, such that some of the mobile terminals being communicating with a cell of the concentrated wireless base station come out of communication with the cell).